Kevin Magnussen says a lack of commitment shown towards him by Renault's management lay at the heart of his departure from the team, with the Dane now set to join Haas.
The 24-year-old was also left unimpressed by Renault's courtship of other drivers for 2017 - joking that "I think at one point the Pope had an offer!"
The build-up to the Brazilian GP has been dominated by moves in F1's midfield driver market.
First, Renault announced Jolyon Palmer would partner the incoming Nico Hulkenberg next season after the British rookie's stronger second half of 2016, before Force India confirmed the signing of Esteban Ocon on the sport's arrival at Interlagos.
Magnussen has insisted it was his decision to leave Renault and cited the length of the contract offered to him - believed to be just one year - as being the key reason for his exit.
Grilled about his future in the Brazilian GP paddock, Magnussen said he was not yet able to confirm his 2017 plans despite widespread reports a minium two-year term at Haas has been agreed.
"It was my decision," he told reporters. "I had an offer, but not a good enough offer that I could take it.
"It was more the failing of commitment from Renault's side. If they had committed to a longer contract I would probably have looked at that much more seriously.
"But it was more the feeling of them not really committing, taking so long and offering the drive to many drivers - I think at one point the Pope had an offer! It was a bit messy, so it's better for me to leave."
Magnussen added that he was kept in the dark about Renault's driver moves with the French team thought to have made approaches for Carlos Sainz and Valtteri Bottas, in addition to Hulkenberg who signed up last month.
Although F1 newcomer Haas have scored 21 more points than Renault, a team a with title-winning history, this year, their respective fortunes could be reversed in 2017 once the French manufacturer's factory might starts to show after a season of rebuilding.
Magnussen, however, believes his 2017 team have strong prospects too.
"I think it could be better - I hope, obviously, it will be better," he added. "It will be competitive."
While Magnussen is heading for his third team in as many racing seasons in F1, Palmer says he is "absolutely delighted" to have been handed a new deal by Renault.
The former GP2 champion believes his stay was earned by his recent results relative to Magnussen on track, with the most recent coming in Mexico when he finished ahead of the sister Renault in 14th from a pitlane start.
"The deciding factor I think has been my rate of progress, recent form, and working hard with the team, putting in a lot of hours at the factory," Palmer said.
"Clearly, the recent form has probably been the biggest thing and it's been getting better and better."
He added: "I thought it would be between me and Kev [for the final seat]. My recent form has been stronger over the second half of the year, and especially in Mexico I did a better race. I felt off the back of all these things that there was a chance, but you never know what's in the minds of the decision makers.
"It was a really good feeling [when I was told]."